1. Field of the Invention
The present invention relates to telecommunications and, more particularly, to the routing of calls over a telecommunication network.
2. General Background
Unspecialized data networks, such as the Internet, have grown in size and scope to the point where they can provide a viable alternative transport system to legacy communications transport media, such as the public switched telephone network (PSTN). Even voice communications, which lead to the development of the PSTN, can now be carried over data networks. Such use of data networks to carry voice is generally known as voice-over-packet service, because it involves using a packet-switched data network for at least a portion of a telephone call connection. In typical carrier-class voice-over-packet systems, the transport media used for any given communication link of a call is transparent to users, especially where the users have not willingly selected an inexpensive alternative to legacy, end-to-end telephone service (for example, when users have made an IP call with a non-standard telephone and expect delays, jitter, and reduced voice quality).
In a typical telecommunications system, calls or telecommunication connections are routed strictly as dictated by the network entities that handle the connection, such as switches and gateways. Regardless of the medium used, if the call is “typical”, in that the caller expects the call to be indistinguishable from a circuit-switched end-to-end connection, the quality of service (QoS) of the call should be relatively high. A high QoS, relatively speaking, is one that has bandwidth, latency, and jitter specifications that provide connection quality equivalent to point-to-point digital private lines. A telecommunication system that operates this way can be unnecessarily expensive, however, and can place a higher than necessary load on system resources if the system's users would be content with lower QoS (such as the QoS that corresponds to Class of Service 2, 3, or 4 for example) for certain types of calls, such as for text messaging applications or short-duration voice calls, and others.